At the children’s playground in the Ukrainian village of Spartak, just outside rebel-held Donetsk, the slide is punctured with shrapnel. Razor-sharp metal lies twisted and distorted, and among the wreckage lie the remains of mortar shells.

The pro-Russian separatists who control the area blame Ukrainian government forces for attacking the village last week.

Ukrainian forces deny breaking the cease-fire and say the separatists, aided by Russian soldiers, continue to fire on their positions. The military said six soldiers were killed Monday and Tuesday.

Journalists take photos and video of the body of a man, a Ukrainian serviceman according to separatist self-proclaimed Donetsk People's Republic (DNR) officials, in Donetsk, April 13, 2015.

Even as the fighting intensified, the foreign ministers of Russia, Ukraine, Germany and France met Monday in Berlin and renewed their commitment to the Minsk cease-fire. German host Frank-Walter Steinmeier said it was a tough meeting, but progress had been made.

He said that in light of the worsening situation, the foreign ministers agreed not only to continue with the withdrawal of heavy weapons, but also to include other categories of weapons, including tanks, armored vehicles, mortars and heavy weapons below a 100-millimeter caliber.

Both sides are weighing the cease-fire deal before fully committing to military withdrawal, said Kadri Liik of the European Council on Foreign Relations.

“Russia is still keeping the military option alive, and there are permanent reports of Russia assembling troops in the area," Liik said. "At the same time, it is also true that some heavy weapons are being removed from the front line. And the diplomatic option is still open as well.”

Liik said Russia’s larger ambitions in Ukraine remained unclear but could involve creating a frozen conflict.

“And that probably would involve a further military offensive," she said. "Because then they would look into making Donbass a more viable ‘statelet.’ That might imply conquer of Mariupol and some more area on the ground, but giving up on ambitions to control Kyiv’s policymaking.”

With the threat of renewed war looming, it is difficult to escape the conflict — even in the classroom.

Students at the Donetsk Mining College in the rebel-held east had a military contest this week titled "I am ready to work and defend my motherland." One competition involved assembling and dismantling an AK-47 rifle. Student Sergei said it is a vital skill.

“If some unwanted people come, then everyone must know how to use it," he said. "It is necessary.”

In government-held Kharkiv, meanwhile, teams of activists used steel cables attached to trucks to tear down Soviet-era statues across the city during the weekend — part of a campaign to rid Ukraine of the icons of its 20th-century past under the former Soviet Union.